The present invention relates to a dielectric ceramic capacitor comprising alternating layers of electrodes and ceramic wherein the ceramic comprises calcium zirconium compounds in a main component.
Ceramic capacitors are known to comprise alternating layers of inner electrodes and ceramic dielectric. There has been, and continues to be, a desire to lower the cost of capacitors without sacrificing the quality. There has also been, and continues to be, a desire to lower the size of capacitors without sacrificing either the quality or capacitance. These desires are often at odds leading those of skill in the art towards continual efforts to advance the art of capacitors and the manufacture thereof.
One advance is the use of nickel as the electrode metal. Nickel has advantages in that the cost is low compared to noble metals such as silver and palladium and the resistance properties are suitable for use in a capacitor. One disadvantage with nickel is the propensity to oxidize under those conditions required to sinter the ceramic dielectric. The problem associated with oxidation has been mitigated by sintering the ceramic in reducing atmosphere thereby insuring that the metal remains in the metallic state. Unfortunately, ceramics sintered in reducing atmosphere have a lower specific resistance which is highly undesirable. This has led to an ongoing effort to develop non-reducible dielectric ceramics which can be sintered in a reducing atmosphere below the melting temperature of nickel.
Towards this goal diligent efforts have led to the development of a non-reducible ceramic which can be sintered in reducing atmosphere without detriment to the electrode thereby yielding a capacitor with high electrode continuity and excellent electrical properties.